I am trying to write a ray tracer to render boxes that are arbitrarily rotated, i.e. not necessarily axis aligned. While I am reasonably comfortable ray tracing an axis-aligned bounding boxes (AABB), I don't know how to handle non-axis aligned objects. The geometry becomes quite difficult. I've looked through a textbook (Ray Tracing from the Ground Up) but couldn't find an answer.
How should I do it? Detailed suggestions would be greatly appreciated.